Downhole motors assemblies are well known in the drilling arts. Mud motors are one well-known type of downhole motors. Mud motors are used to supplement drilling operations by turning hydraulic power into mechanical torque and applying this torque to a drill bit. The mud (i.e., drilling fluid) is used to cool and lubricate the drill bit, to carry away drilling debris, and to provide a mud cake on the walls of the annulus to prevent the hole from sloughing in upon itself or from caving in all together. Mud motors are an integral component of a downhole drilling string, which allows a drill bit to be driven using hydraulic horsepower from the circulated drilling mud without requiring the drill pipe to be rotated at the surface. This technology has been used for decades in the oil and gas industry, and is of significant importance in drilling directional, non-linear wellbores since the mud motor can be used in an off-set orientation to “steer” a drill string in a pre-determined direction. The sealed bearing pack is one part of the mud motor and is used to seal the bearings in a “clean” environment where the moving parts in the sealed bearing pack are not exposed to drilling mud, thus extending the life of the mud motor and saving considerable time and expense during drilling operations.
Mud motors operate in very high pressure and high torque operations and are known to fail in certain, predictable ways. The failure of a mud motor is very expensive, as the whole drill string must be pulled out of the bore hole in order to bring the mud motor to the surface where it can be repaired or replaced. This is a very time consuming and costly operation considering the drilling operations must be halted while the drill string and bottom hole assembly are tripped from the wellbore. Common problems that occur with prior art mud motors include: seal failure resulting in drilling mud contaminating the universal joint in the transmission section; pressuring up, often called hydraulically locking, due to either fluid or gas being trapped within the confines of the tool itself; broken bearing mandrels resulting in mud entering into the bearings; and slap, the bouncing around or moving of the thrust bearings.